package audit

import (
	"context"
	"fmt"
	"sort"
	"strconv"
	"time"

	"github.com/break/junhong_cmp_fiber/internal/model"
	retentionquery "github.com/break/junhong_cmp_fiber/internal/query/retention"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
)

// LinkTimeline 是 request 或 correlation 的跨事实只读时间线。
type LinkTimeline struct {
	RequestID                *string             `json:"request_id" description:"本次按请求查询的稳定ID"`
	CorrelationID            *string             `json:"correlation_id" description:"本次按业务关联查询的稳定ID"`
	AccessLogLookupRequestID *string             `json:"access_log_lookup_request_id" description:"可复制到Access Log检索的request_id；本接口自身不扫描Access Log"`
	Nodes                    []LinkTimelineNode  `json:"nodes" description:"跨事实来源按发生时间稳定排序的节点"`
	Retention                retentionquery.Info `json:"retention" description:"Audit与Integration共同在线留存边界"`
}

// LinkTimelineNode 是保留各事实源权威边界的时间线节点。
type LinkTimelineNode struct {
	RecordSource      string                     `json:"record_source" enum:"audit_event,integration_log,outbox_event,asynq_task,domain_ledger_ref" description:"事实来源 (audit_event:审计事件, integration_log:外部交互, outbox_event:可靠事件引用, asynq_task:异步任务引用, domain_ledger_ref:业务账本引用)"`
	NodeID            string                     `json:"node_id" description:"该事实来源内的稳定节点ID"`
	OccurredAt        time.Time                  `json:"occurred_at" description:"节点发生时间"`
	Code              string                     `json:"code" description:"来源内稳定动作、操作或事件编码"`
	Title             string                     `json:"title" description:"code对应的中文展示名称"`
	Result            string                     `json:"result" description:"来源内原始结果稳定编码"`
	ResultName        string                     `json:"result_name" description:"result对应的中文展示名称"`
	Summary           string                     `json:"summary" description:"已脱敏节点摘要"`
	ReferenceOnly     bool                       `json:"reference_only" description:"true表示仅保存其他事实的引用，不代表该来源独立完成业务状态变更"`
	RequestID         *string                    `json:"request_id" description:"HTTP请求关联ID"`
	CorrelationID     *string                    `json:"correlation_id" description:"跨请求业务链路ID"`
	ParentEventID     *string                    `json:"parent_event_id" description:"父审计事件ID"`
	Resources         []InvestigationResourceRef `json:"resources" description:"节点可稳定定位的资源引用"`
	InvestigationRefs InvestigationRefs          `json:"investigation_refs" description:"可继续跳转的稳定调查引用"`
	Fidelity          LinkageFidelity            `json:"fidelity" description:"历史字段完整度和可关联能力"`
}

// LinkageFidelity 明确节点已有的稳定关联能力，不补猜历史缺失字段。
type LinkageFidelity struct {
	RequestAvailable         bool `json:"request_available" description:"是否有稳定request_id"`
	CorrelationAvailable     bool `json:"correlation_available" description:"是否有稳定correlation_id"`
	ParentEventAvailable     bool `json:"parent_event_available" description:"是否有稳定parent_event_id"`
	DirectAuditLinkAvailable bool `json:"direct_audit_link_available" description:"是否可直接跳转审计事件详情"`
	StableResourceAvailable  bool `json:"stable_resource_available" description:"是否至少有一个含resource_id的稳定资源引用"`
}

// RequestTimeline 按精确 request ID 组合已持久化事实，不扫描 Access Log。
func (q *Query) RequestTimeline(ctx context.Context, requestID string) (*LinkTimeline, error) {
	return q.linkTimeline(ctx, "request_id", requestID)
}

// CorrelationTimeline 按精确 correlation ID 组合跨请求业务链路。
func (q *Query) CorrelationTimeline(ctx context.Context, correlationID string) (*LinkTimeline, error) {
	return q.linkTimeline(ctx, "correlation_id", correlationID)
}

func (q *Query) linkTimeline(ctx context.Context, column, value string) (*LinkTimeline, error) {
	if err := q.authorize(ctx); err != nil {
		return nil, err
	}
	if value == "" || (column != "request_id" && column != "correlation_id") {
		return nil, errors.New(errors.CodeInvalidParam)
	}

	retention, err := retentionquery.Load(ctx, q.db, retentionquery.SourceAudit, retentionquery.SourceIntegration)
	if err != nil {
		return nil, err
	}
	auditRows, integrationRows, outboxRows, err := q.loadLinkRows(ctx, column, value, retention.OnlineFrom)
	if err != nil {
		return nil, err
	}
	events, err := q.project(ctx, auditRows)
	if err != nil {
		return nil, err
	}

	nodes := make([]LinkTimelineNode, 0, len(events)+len(integrationRows)+len(outboxRows))
	integrationByAudit := integrationRefsByAuditID(integrationRows)
	for index, event := range events {
		refs := event.InvestigationRefs
		refs.IntegrationRefs = append(refs.IntegrationRefs, integrationByAudit[auditRows[index].ID]...)
		refs.IntegrationRefs = append(refs.IntegrationRefs, integrationResourceRefs(event.Resources)...)
		refs.IntegrationRefs = uniqueIntegrationRefs(refs.IntegrationRefs)
		nodes = append(nodes, auditTimelineNode(event, refs))
		nodes = append(nodes, resourceReferenceNodes(event, refs)...)
	}
	for _, row := range integrationRows {
		nodes = append(nodes, integrationTimelineNode(row))
	}
	for _, row := range outboxRows {
		nodes = append(nodes, outboxTimelineNode(row))
	}
	sort.Slice(nodes, func(i, j int) bool {
		if nodes[i].OccurredAt.Equal(nodes[j].OccurredAt) {
			if nodes[i].RecordSource == nodes[j].RecordSource {
				return nodes[i].NodeID < nodes[j].NodeID
			}
			return nodes[i].RecordSource < nodes[j].RecordSource
		}
		return nodes[i].OccurredAt.Before(nodes[j].OccurredAt)
	})

	timeline := &LinkTimeline{Nodes: nodes, Retention: retention}
	if timeline.Nodes == nil {
		timeline.Nodes = []LinkTimelineNode{}
	}
	if column == "request_id" {
		timeline.RequestID = stringPointer(value)
		timeline.AccessLogLookupRequestID = stringPointer(value)
	} else {
		timeline.CorrelationID = stringPointer(value)
	}
	return timeline, nil
}

func (q *Query) loadLinkRows(ctx context.Context, column, value string, onlineFrom time.Time) ([]model.AuditEvent, []model.IntegrationLog, []model.OutboxEvent, error) {
	auditRows := []model.AuditEvent{}
	if err := q.db.WithContext(ctx).Where(column+" = ? AND occurred_at >= ?", value, onlineFrom.UTC()).Find(&auditRows).Error; err != nil {
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询链路审计事件失败")
	}
	integrationRows := []model.IntegrationLog{}
	if err := q.db.WithContext(ctx).Where(column+" = ? AND created_at >= ?", value, onlineFrom.UTC()).Find(&integrationRows).Error; err != nil {
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询链路外部交互失败")
	}
	outboxRows := []model.OutboxEvent{}
	if err := q.db.WithContext(ctx).Where(column+" = ? AND created_at >= ?", value, onlineFrom.UTC()).Find(&outboxRows).Error; err != nil {
		return nil, nil, nil, errors.Wrap(errors.CodeDatabaseError, err, "查询链路可靠事件失败")
	}
	return auditRows, integrationRows, outboxRows, nil
}

func auditTimelineNode(event EventView, refs InvestigationRefs) LinkTimelineNode {
	return LinkTimelineNode{
		RecordSource: constants.AuditRecordSourceAuditEvent, NodeID: event.EventID,
		OccurredAt: event.OccurredAt, Code: event.ActionCode, Title: event.ActionName,
		Result: event.Result, Summary: event.Summary,
		RequestID: stringPointer(event.RequestID), CorrelationID: stringPointer(event.CorrelationID),
		ParentEventID: stringPointer(event.ParentEventID), Resources: refs.ResourceRefs, InvestigationRefs: refs,
		Fidelity: linkageFidelity(event.RequestID, event.CorrelationID, event.ParentEventID, true, len(refs.ResourceRefs) > 0),
	}
}

func integrationTimelineNode(row model.IntegrationLog) LinkTimelineNode {
	resource := integrationResourceRef(row)
	resources := make([]InvestigationResourceRef, 0, 1)
	if resource != nil {
		resources = append(resources, *resource)
	}
	refs := InvestigationRefs{
		ResourceRefs: resources, RequestID: row.RequestID, CorrelationID: row.CorrelationID,
		IntegrationRefs: []IntegrationRef{{IntegrationID: row.IntegrationID}},
	}
	return LinkTimelineNode{
		RecordSource: constants.AuditRecordSourceIntegrationLog, NodeID: row.IntegrationID,
		OccurredAt: row.CreatedAt, Code: row.Operation,
		Title:  constants.IntegrationProviderName(row.Provider) + " · " + constants.IntegrationOperationName(row.Operation),
		Result: row.Result, ResultName: constants.IntegrationResultName(row.Result), Summary: "外部交互事实",
		RequestID: row.RequestID, CorrelationID: row.CorrelationID, Resources: resources, InvestigationRefs: refs,
		Fidelity: linkageFidelity(pointerValue(row.RequestID), pointerValue(row.CorrelationID), "", row.AuditEventID != nil, resource != nil),
	}
}

func outboxTimelineNode(row model.OutboxEvent) LinkTimelineNode {
	resourceType := row.ResourceType
	if resourceType == "" {
		resourceType = row.AggregateType
	}
	resourceID := row.ResourceID
	if resourceID == "" {
		resourceID = row.AggregateID
	}
	resourceKey := row.BusinessKey
	if resourceKey == "" {
		resourceKey = row.AggregateID
	}
	resource := InvestigationResourceRef{ResourceType: resourceType, ResourceID: stringPointer(resourceID), ResourceKey: resourceKey, DisplayName: resourceKey}
	refs := InvestigationRefs{
		ResourceRefs: []InvestigationResourceRef{resource}, RequestID: stringPointer(row.RequestID),
		CorrelationID: stringPointer(row.CorrelationID), IntegrationRefs: []IntegrationRef{},
	}
	return LinkTimelineNode{
		RecordSource: constants.AuditRecordSourceOutboxEvent, NodeID: row.EventID,
		OccurredAt: row.CreatedAt, Code: row.EventType, Title: "可靠事件：" + row.EventType,
		Result: strconv.Itoa(row.Status), ResultName: constants.GetOutboxStatusName(row.Status),
		Summary:   fmt.Sprintf("%s/%s，重试 %d 次", row.AggregateType, row.AggregateID, row.RetryCount),
		RequestID: stringPointer(row.RequestID), CorrelationID: stringPointer(row.CorrelationID),
		ParentEventID: stringPointer(row.ParentEventID), Resources: refs.ResourceRefs, InvestigationRefs: refs,
		Fidelity: linkageFidelity(row.RequestID, row.CorrelationID, row.ParentEventID, row.ParentEventID != "", resourceType != "" && resourceID != ""),
	}
}

func resourceReferenceNodes(event EventView, refs InvestigationRefs) []LinkTimelineNode {
	nodes := make([]LinkTimelineNode, 0, len(event.Resources))
	for _, resource := range event.Resources {
		recordSource := ""
		titlePrefix := ""
		summary := ""
		switch {
		case isAsynqTaskResource(resource.ResourceType):
			recordSource = constants.AuditRecordSourceAsynqTask
			titlePrefix = "异步任务："
			summary = "持久化任务资源摘要；不读取或推断 Redis 队列历史"
		case isDomainLedgerResource(resource.ResourceType):
			recordSource = constants.AuditRecordSourceDomainLedgerRef
			titlePrefix = "业务账本引用："
			summary = "状态、金额及业务结论以对应业务表为准"
		default:
			continue
		}
		resourceRef := InvestigationResourceRef{ResourceType: resource.ResourceType, ResourceID: resource.ResourceID, ResourceKey: resource.ResourceKey, DisplayName: resource.DisplayName}
		nodeRefs := refs
		nodeRefs.ResourceRefs = []InvestigationResourceRef{resourceRef}
		nodes = append(nodes, LinkTimelineNode{
			RecordSource: recordSource,
			NodeID:       fmt.Sprintf("%s:%s:%s:%s:%s", event.EventID, resource.ResourceType, pointerValue(resource.ResourceID), resource.ResourceKey, resource.Role),
			OccurredAt:   event.OccurredAt, Code: resource.ResourceType, Title: titlePrefix + resource.DisplayName,
			Result: event.Result, Summary: summary, ReferenceOnly: true,
			RequestID: stringPointer(event.RequestID), CorrelationID: stringPointer(event.CorrelationID),
			ParentEventID: stringPointer(event.ParentEventID), Resources: nodeRefs.ResourceRefs, InvestigationRefs: nodeRefs,
			Fidelity: linkageFidelity(event.RequestID, event.CorrelationID, event.ParentEventID, true, resource.ResourceID != nil || resource.ResourceKey != ""),
		})
	}
	return nodes
}

func integrationRefsByAuditID(rows []model.IntegrationLog) map[uint][]IntegrationRef {
	refs := make(map[uint][]IntegrationRef)
	for _, row := range rows {
		if row.AuditEventID != nil {
			refs[*row.AuditEventID] = append(refs[*row.AuditEventID], IntegrationRef{IntegrationID: row.IntegrationID})
		}
	}
	return refs
}

func integrationResourceRefs(resources []ResourceView) []IntegrationRef {
	refs := make([]IntegrationRef, 0)
	for _, resource := range resources {
		if resource.ResourceType == constants.AuditResourceIntegrationLog && resource.ResourceKey != "" {
			refs = append(refs, IntegrationRef{IntegrationID: resource.ResourceKey})
		}
	}
	return refs
}

func uniqueIntegrationRefs(refs []IntegrationRef) []IntegrationRef {
	unique := make([]IntegrationRef, 0, len(refs))
	seen := make(map[string]bool, len(refs))
	for _, ref := range refs {
		if ref.IntegrationID == "" || seen[ref.IntegrationID] {
			continue
		}
		seen[ref.IntegrationID] = true
		unique = append(unique, ref)
	}
	return unique
}

func integrationResourceRef(row model.IntegrationLog) *InvestigationResourceRef {
	if row.ResourceType == nil || *row.ResourceType == "" {
		return nil
	}
	ref := InvestigationResourceRef{ResourceType: *row.ResourceType, ResourceID: row.ResourceID}
	if row.ResourceKey != nil {
		ref.ResourceKey = *row.ResourceKey
		ref.DisplayName = *row.ResourceKey
	}
	return &ref
}

func linkageFidelity(requestID, correlationID, parentEventID string, directAuditLink, stableResource bool) LinkageFidelity {
	return LinkageFidelity{
		RequestAvailable: requestID != "", CorrelationAvailable: correlationID != "",
		ParentEventAvailable: parentEventID != "", DirectAuditLinkAvailable: directAuditLink,
		StableResourceAvailable: stableResource,
	}
}

func pointerValue(value *string) string {
	if value == nil {
		return ""
	}
	return *value
}

func isAsynqTaskResource(resourceType string) bool {
	switch resourceType {
	case constants.AuditResourceDeviceBatchTask, constants.AuditResourceIotCardImportTask,
		constants.AuditResourceDeviceImportTask, constants.AuditResourceAssetPackageBatchOrderTask,
		constants.AuditResourceOrderPackageInvalidateTask, constants.AuditResourceExportTask:
		return true
	default:
		return false
	}
}

func isDomainLedgerResource(resourceType string) bool {
	switch resourceType {
	case constants.AuditResourceOrder, constants.AuditResourcePayment, constants.AuditResourceRefund,
		constants.AuditResourceAgentRecharge, constants.AuditResourceRechargeOrder,
		constants.AuditResourceAssetWallet, constants.AuditResourceAssetWalletTransaction,
		constants.AuditResourceAgentWallet, constants.AuditResourceAgentWalletTransaction,
		constants.AuditResourceAgentWalletReservation, constants.AuditResourcePackageUsage,
		constants.AuditResourceApprovalInstance, constants.AuditResourceCommissionRecord,
		constants.AuditResourceCommissionWithdrawal:
		return true
	default:
		return false
	}
}